Carbon-brush connection.



F. HAUSEN.

CARBON BRUSH CONNECTION.

APPUCATION FILED APR. I4. 1915.

Patented Dec. 12, 1916.

a 4 3 3 A .J 22525553592 n Ma 3 WITNESS UNITED STATES PATENT OFFICE.

RAYMOND F. HAUSEN, 0F PITTSBURGH, PENNSYLVANIA.

CARBON-BRUSH CONNECTION.

Application filed April 14, 1915.

To all whom it may concern Be it known that I, RAYMOND F. HAUsnN, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Carbon-Brush Connections, of which the following is a specification.

My invention relates to carbon brushes for electrical machines such as generators and motors, and more particularly to means for attaching electrical conductors to such brushes.

One object of my invention is the provision of means for attaching the conductor to the brush in such manner that the conductor is held rigidly in position and cannot work loose, and so that the conductor cannot be removed from the brush after it has been attached thereto.

A further object is to provide attaching means of this character which will insure a contact of very low resistance between the brush and the conductor.

I will describe certain forms of attaching means embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Figure 1 is a view showing a brush and one form of conductor-attaching means embodying my invention, the brush being partly broken away to clearly show the structure. Fig. 2 is a view showing the device shown in Fig. 1 during the process of assembling. Fig. 3 is a view showing the device shown in Fig. 1 after the conductor and the conductor-attaching member have been cut off flush with the surface of the brush. Fig. is a view showing the conductor-attaching member 3 shown in the preceding views. Figs. 5 and 6 are views showing modified forms of the member shown in Fig. 4. Figs. 7 and 8 are views showing another modified form of the conductor-attaching member and also embodying my invention.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Figs. 1 and 2, the reference character 1 designates the carbon brush, which is provided with a cylindrical aperture 5'adapted to receive the conductor 2. This conductor is finally a xible type,

Specification of Letters Patent.

Patented Dec. 12, 1916.

Serial No. 21,305.

such as a woven or stranded conductor. Surrounding the conductor 2 within the brush is a cylindrical member 3 which in the form shown in Figs. 1 to L, is a screw ha ing a longitudinal bore adapted to receive the conductor. The screw is also provided with longitudinal slots 3, by virtue of which the screw may be spread open to receive the conductor.

To assemble the parts, the end of the conductor 2 is first passed through the aperture 5 and into the bore of the screw 3, as shown in Fig. 2. The screw is then turned into the aperture 5. The aperture may, if desired, be provided with threads matching those on the screw, but I have found that in most cases this is unnecessary for the reason that the screw will make its own threads in the carbon as it is turned in. After the screw is turned into place, it may be cut off flush with the surface of the brush, as shown in Fig. 3, so that it cannot be removed.

Preferably the diameter of the bore in the screw 3 is slightly less than the diameter of the conductor 2, so that when the conductor is inserted in the bore, the screw is spread to a diameter somewhat greater than normal. The diameter of the aperture 5, however, corresponds to the normal diameter of the screw. Hence when the screw is turned into the brush it compresses the conductor, so that the conductor is securely gripped and a very low-resistance contact between the screw and the conductor is insured. A low resistance contact between the screw and the brush is also insured because of the outward pressure of the conductor on the screw. The surface of the bore in screw 3 is preferably roughened as indicated in Figs. 4 and 5, thus increasing the grip between the conductor and the screw.

If desired, the screw 3 may be provided with only one longitudinal slot 3 as shown in Fig. 5; I do not wish to limit myself to any specific number of such slots.

The member which surrounds the conductor may, if desired, be a plain cylindrical tube las shown in Fig. 6, the tube being provided with one or more slots 1 for the same purpose as the slots 3 in the screw. In this case the process of assembling the parts will be the same as before except that the tubular member 4: will be driven straight into the aperture 5 in the brush. As shown in Fig. 6 the tube is provided with two slots so that the tube comprises two separate sections, but I do not wish to limit myself to any specific number of such slots.

In the modification of my invention shown in Figs. 7 and 8, the member which surrounds the conductor is formed in two semicylindrical parts 6, 6, each of which is threaded on the outside so that when the parts are placed together they form in effeet a screw. In assembling this form of the device, the parts 6, 6 are first placed together with the conductor 2 between them as shown in Fig. 8, and the parts are then gripped near one end by a suitable special tool and turned into the aperture in the brush. in the same manner as the screw shown in Fig. l or 5. The parts 6, 6 and the conductor are then cut oil? flush with the sur face of the brush as in the case of the other modifications hereinbefore explained. The advantage of the form shown in Figs. 7 and 8 over the screws shown in Figs. t and 5 is that the parts 6, 6 may be formed-by stamping, whereas the screws must be turned; the cost of stamping is of course less than that of turning.

It will be clear that when the conductor is once attached to the brush by my improved means, it cannot work loose, and it cannot be removed to insert another conductor. This prevents removal of the conductor from a brush which is worn down, and inserting this conductor in another brush which may be called upon to carry more current than the conductor is adapted to carry.

The conductor can of course be removed by breaking away the brush, but this renders the brush unfit for further service; such a conductor when once removed cannot usually be inserted in another brush because with the forms shown in Figs. 1 and 2 the screw head has been cut OE, and with the other forms a special tool is required to apply the conductor to another brush, which tool is not likely to be in the hands of a dynamo or motor attendant.

Although I have herein shown only certain forms of conductor-attaching means embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is 1. In combination, a carbon brush having a cylindrical aperture therein, a flexible conductor extending into said aperture, and a cylindrical member of conductive material located also in said aperture and surrounding said conductor, said member having one or more longitudinal slots whereby it is compressed tightly around the conductor when driven into said aperture.

2. In combination, a carbon brush having a cylindrical aperture therein, a flexible conductor extending into said aperture, and a cylindrical member of conductive material surrounding said conductor and having one or more longitudinal slots, said member being of such size that when it is driven into the brush it is compressed tightly around the conductor.

8. In combination, a carbon brush having a cylindrical aperture therein, a flexible conductor extending into said aperture, a cylindrical screw adapted to be turned into said aperture and having a longitudinal bore adapted to receive said conductor, said screw having one or more longitudinal slots, and the bore being of such size as to require that the screw be spread at the slot or slots to admit the conductor, whereby when the screw is turned into the aperture it is caused to grip the conductor so that the latter cannot then be withdrawn.

4:. In combination, a carbon brush having a cylindrical aperture therein, a flexible conductor extending into said aperture, a cylindrical member of conductive material adapted to be driven into said aperture and having a longitudinal bore adapted to receive said conductor, said member having also one or more longitudinal slots, the bore of said member being of such size as to require that the member be spread at the slot or slots to admit the conductor, and the size of said aperture being substantially the same as the normal size of the outside of said member, whereby when the member is driven into the brush it is caused to grip the conductor so that the latter cannot then be withdrawn.

5. In combination, a carbon brush having a cylindrical aperture therein, a flexible con ductor extending into said aperture, a cylindrical member of conductive material adapted to be driven into said aperture and having a longitudinal bore adapted to receive said conductor, said member having also one or more longitudinal slots, the bore of said member being of such size as to re quire that the member be spread at the slot or slots to admit the conductor, and the size of said aperture being substantially the same as the normal size of the outside of said member, whereby when the member is driven into the brush it is caused to grip the conductor so that the latter cannot then be withdrawn, and the bore in said member being roughened to increase its grip on the conductor.

6. In combination, a carbon brush having a cylindrical aperture therein, a flexible conductor extending into said aperture, and a cylindrical member of conductive material formed of two or more longitudinal parts located also in said aperture and surroundwith screw threads whereby the member 10 ing said conductor. may be turned into said aperture.

7. In combination, a carbon brush having In testimony whereof I aflix my signature a cylindrical aperture therein, a flexible con in presence of two witnesses. 5 ductor extending into said aperture, and a cylindrical member of conductive material RAYMOND formed of two or more longitudinal parts Witnesses:

adapted to surround said conductor the L. H. MCOABE,

outer surfaces of said parts being provided A. S. CANNON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C. 

